In recent years, power storage devices such as lithium ion secondary batteries, lithium ion capacitors, and air cells have been developed.
An electrode for a power storage device is manufactured by providing an active material over a surface of a current collector. As the active material, a material such as carbon or silicon, which can store and release ions serving as carriers, is used. For example, silicon or phosphorus-doped silicon has higher theoretical capacity than carbon and is advantageous in increasing the capacity of a power storage device (e.g., Patent Document 1).